Apparatus for continuously heating wire



Sept. 22, 1970 w; HENR|H 3,530,274

APPARATUS FOR CONTINUOUSLY HEATING WIRE Filed Aug. 50, 1968 a l I I 10 9I l u 5 I I r- LII] lNVE/VTOR ERNER HENRICH Arrow/v5? United StatesPatent 3,530,274 APPARATUS FOR C(V)VNT:I IUOUSLY HEATING IR WernerHenrich, 16 Jahnstrasse, 6349 Merkenbach, Germany Filed Aug. 30, 1968,Ser. No. 756,610 Claims priority, application Germany, Sept. 5, 1967,1,583,367 Int. Cl. C2141 9/62; Hd N00 US. Cl. 219-155 1 Claim ABSTRACTOF THE DISCLOSURE The present invention relates to the continuousheating of wires, strands, cables and the like, more particularly, to anapparatus for preventing forces caused by fluctuations in speed of themoving wire resulting from the rewinding process from being transmittedto the wire while it is being heated.

In the manufacture of wire, strands, cables of indeterminated length andthe like it is frequently desired to heat such wires. This can beaccomplished by passing the wire through a heating zone and then througha cooling zone after which the wire is rewound. The heating can be doneelectrically by passing the moving wire over an electrically conductingroller positioned at the beginning of the heating zone and driven by anadjustable permanent magnetic clutch. This arrangement has the advantageof permitting the wire to move over the current carrying roller withoutslipping and thus prevents the formation of burned areas on the wire.This form of apparatus has been satisfactory in operation since it canbe adjusted so that the wire will almost be pushed into the heating zoneinstead of being pulling therein. In addition, another driven roller maybe provided at the exit of the heating zone so that the forces actingupon the wire while it is in the heating zone will be balanced andthereby prevent any undesirable stretching or elongation of the wirewhile it is in the heating zone.

After heating, the wire is then cooled, and if necessary dried, afterwhich the Wire is wound upon a suitable spool or reel. It is known inthe art that the speed of rotation of this rewinding spool must becontinually changed as the wound wire accumulates on the spool. However,it is difficult to accurately regulate this adjustment in the rotationalspeed of the spool to prevent all stretching of the wire during thisrewinding process. It has therefore been proposed to drive the rewindingspool by means of a permanent magnetic clutch to provide a resilientdriving connection. This arrangement has not been completelysatisfactory since variations and fluctuations in the speed of themoving wire during the rewinding were apparent in the heating zone.During heating the wire is relatively soft and readily susceptible tostretching caused by these speed fluctuations. These undesirable effectsare quite serious with relatively thin wires.

It is therefore the principal object of the present invention to providea novel and improved apparatus for Patented Sept. 22, 1970 preventingundesirable stretching of moving wire while 1t is being heated.

It is another object of the present invention to provide a simple andinexpensive arrangement for preventing any stretching or burned areas ina wire while it is in the heated zone because of fluctuations in thespeed of rewinding the wire.

The apparatus according to the present invention essentially comprisesmeans for passing an electric current through a portion of a moving wireas it emerges from a wire drawing apparatus to define a heating zone soas to heat the wire to incandescence. The heating means may include anelectrically conducting roller over which the wire passes with thisroller being positioned at the beginning of the heating zone. Theelectrically conducting roller is driven by a permanent magnet clutch toprovide a resilient driving connection. After the wire is heated it ispassed through a cooling zone. After emerging from the cooling zone thewire is rewound upon a suitable roller or the like. Interposed betweenthe heating zone and the rewinding roller there is provided roller meansfor carrying the moving wire and for absorbing any fluctuations in thespeed of the moving wire resulting from variations in the speed at whichthe wire is wound on the rewinding roller so that such speedfluctuations are not transmitted to the wire in the heated zone. Theroller means may comprise several rollers which are driven resilientlythrough permanent magnet clutches. These rollers thus operate in themanner of buffers or absorbers in that any sudden jerks to the wiredelivered by the rewinding roller are absorbed by the resiliently drivenroller immediately ahead of the rewinding roller.

Other objects and advantages of the present invention will be apparentupon reference to the drawing which illustrates schematically theapparatus according to the present invention.

With reference to the drawing a specific embodiment of the presentinvention will be described in detail. From a wire drawing apparatus 1,such as well known in the art, a wire 2 emerges and passes over rollers3, 4 and 5 onto a rewinding spool 6. The rollers 3, 4 and 5 areresiliently driven respectively through permanent magnet clutches 7, 8and 9. The clutches are known in the art and may be electricallyactuated.

The rollers 3 and 4 are electrically conducting and are connectedthrough suitable leads to a source of electrical energy 10 so that anelectric current is passed through that portion of the wire between therollers 3 and 4. This portion of the wire defines a heating zone 11within which the wires are heated so as to be brought to incandesence.

Between the rollers 4 and 5 the wire passes through a ZOne 12 in whichit is cooled. If a fluid cooling medium is used then the wire is alsodried within this zone.

It is apparent that within the heating zone 11 the wire is the mostsusceptible to tensile forces of the kind resulting from fluctuations inthe speed of movement of the wire because of variations in the windingspeed of spool 6. The wire in zone 11, being in a heated state, isrelatively soft. 'Ihis sensitivity to tensile forces progressi'velydiminishes as the wire is cooled in the zone 12.

During the rewinding of the wire upon the spool 6, any variations orfluctuations in the rotational speed of the spool 6 will exert astronger pulling or tensile force on the wire. A portion of thisincreased tensile force will be absorbed by the resilient drive which isconventionally provided to drive rewinding spool 6. A residual portionof this increased tensile force will also be absorbed by the resilientlydriven roller 5 so that in the cooling zone 12 the wire will besubjected only to those forces which would no longer cause any permanentdeformation of the wire. Any remaining portions of the abrupt tensileforce will finally be absorbed by the resiliently driven roller 4 sothat that portion of the wire which is in the heating zone 11 will notbe subjected to any undesired tensile forces. Thus that portion of thewire within the heating zone 11 will be subjected to a substantiallyuniform tensile force during the winding operation. Any sudden increasesin tensile forces in the wire imparted by the spool 6 will be absorbedbefore these forces can be transmitted to the portion of the wire withinthe heating zone.

The above described apparatus has been found to be particularly suitablefor very thin wires in that it will prevent any undesirable stretching,deformation or burned areas in these wires which previously might becaused by changes in the rotational speed of the rewinding spool. Suchthin wire may be -15 microns in diameter.

The resilient or elastic clutches, such as 7, 8 and 9 are known in theart and the clutch disclosed in German Pat. 849,272 of Sept. 11, 1952 issuitable for use in this invention. The resiliency of the clutches is soselected to depend largely on the material of the wire being drawn andon the thickness or diameter of the drawn wire.

Thus it can be seen that the present invention has disclosed anapparatus which is inexpensive and simple in structure for preventingthe transmission of undesirable tensile forces to that portion of amoving wire which is in a heated condition. The present invention isreadily applicable for use in drawing thick wires as well as in drawingvery fine wires. The apparatus effectively absorbs all abrupt increasesin tensile force exerted on the wire because of variations orfluctuations in the rotational speed of the rewinding spool. Byeffectively absorbing such tensile forces so that they cannot betransmitted to the wire in the heated condition, the wire in the heatingzone is subjected to a uniform tensile force. The resulting wire istherefore free of undesirable stretching, deformation or burned areas.

4 It will be understood that this invention is subject to modificationin order to adapt it to different uses and conditions.

What is claimed is:

1. In an apparatus for continuously heating and cooling very thin wire,the combination of means for passing an electric current through aportion of a moving wire emerging from a wire drawing apparatus todefine a heating zone to heat the wire, first and second spacedelectrically conducting rollers over which the wire passes and connectedto a source of electrical energy with said first and second electricallyconducting rollers defining the heating zone, first and second magneticclutches drivingly connected to said first and second electricallyconducting rollers respectively to resiliently drive the same, meanssubsequent to said second electrically conducting roller and saidheating means through which the wire passes for cooling the heated wire,a rewinding spool being resiliently driven to receive the wire afteremerging from said cooling means, a third roller positioned after saidcooling means and before said rewinding spool and carrying the movingwire, a third magnetic clutch drivingly connected to said third rollerto drive resiliently the same, said third and second magnetic clutchdriven rollers absorbing progressively fluctuations in the speed of themoving wire resulting from variations in the speed at which the wire isWound on the rewinding spool to decrease progressively the effect offluctuations of the rewinding speed on the tension of the wire movingthrough the heating zone.

References Cited UNITED STATES PATENTS 2,976,397 3/1961 Ellis 219-3,328,554 6/1967 Biskeborn 2l9l55 2,993,114 7/1961 Bunch et al. 219-455JOSEPH V. TRUHE, Primary Examiner L. A. ROUSE, Assistant Examiner

